Screw for joint fusion

ABSTRACT

Techniques for joint fusion are described, including a screw comprising a head having a partially flat surface and an opening for receiving a screwdriver tip, the head able to fit within a drill guide, a tip having another opening, a shaft extending from the head to the tip, the shaft having a plurality of holes and a thread on an external surface of the shaft, and a cannula within the shaft extending from the opening to the another opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending U.S. patent applicationSer. No. 13/942,672, filed Jul. 15, 2013 and entitled, “SCREW FOR JOINTFUSION”, which is a continuation of U.S. patent application Ser. No.13/571,126, filed Aug. 9, 2012 and entitled, “JOINT FUSION”; thisapplication is also a continuation of copending U.S. patent applicationSer. No. 13/942,673, filed on Jul. 15, 2013 and entitled, “SCREW FORJOINT FUSION”, which is a continuation of U.S. patent application Ser.No. 13/571,126, filed Aug. 9, 2012 and entitled, “JOINT FUSION”; thisapplication is also a continuation of copending U.S. patent applicationSer. No. 14/191,370, filed Feb. 26, 2014 and entitled, “SCREW FOR JOINTFUSION”, which is a divisional of U.S. patent application Ser. No.13/942,673, filed on Jul. 15, 2013 and entitled, “SCREW FOR JOINTFUSION”, which is a continuation of U.S. patent application Ser. No.13/571,126, filed Aug. 9, 2012 and entitled, “JOINT FUSION”; all ofwhich are incorporated by reference herein in their entirety for allpurposes.

FIELD

The present invention relates generally to orthopedic surgery. Morespecifically, techniques associated with a screw for joint fusion aredescribed.

BACKGROUND

Stress across joints generally is a common cause of pain. Stress acrossthe sacroiliac joint is a common source of lower back pain. Suchsacroiliac joint stress, including sacroiliac joint disruptions (i.e.,separations) and degenerative sacroiliitis (i.e. inflammation), canresult from lumbar fusion, trauma, postpartum, heavy lifting, arthritis,or unknown causes. Sacroiliac joint fixation or arthrodesis is sometimesrecommended for skeletally mature patients with severe, chronicsacroiliac joint pain or acute trauma in the sacroiliac joint.

Conventional solutions for stabilizing joints and relieving pain injoints typically include the insertion of an implant, such as a metalscrew, rod or bar, laterally across the joint. However, conventionalsolutions can involve invasive surgical procedures. Furthermore, evenmore minimally invasive procedures have drawbacks. One drawback ofconventional solutions for sacroiliac joint fixation is the inability todeliver materials, such as osteogenic, osteoconductive, other boneregenerative materials, antibiotics, steroids, and other joint treatmentmaterials (i.e., for inflammation or infections), to the bones throughimplants and an implantation procedure that is minimally invasive.Another drawback of conventional implants for sacroiliac joint fixationis that they do not allow for bone growth into and through the implantfor true fusion of the joint. Finally, conventional implantationsolutions do not provide methods for delivering such joint stresstreatment materials through the implant at a later time (i.e.,post-implantation).

Thus, techniques for joint fusion without the limitations ofconventional techniques are needed.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments or examples (collectively “examples”) of theinvention are disclosed in the following detailed description and theaccompanying drawings:

FIGS. 1A-1C illustrate a side view, a perspective view and across-section view, respectively, of an exemplary screw for jointfusion;

FIGS. 2A-2B illustrate a side view and a perspective view, respectively,of an alternative exemplary screw for joint fusion;

FIG. 3A illustrates a top view of an exemplary screw for joint fusion;

FIG. 3B illustrates a bottom view of an exemplary screw for jointfusion;

FIG. 4A illustrates an exemplary drill guide assembly having a pinsleeve and a drill guide;

FIG. 4B illustrates an exemplary drill guide assembly placed over aguide pin;

FIGS. 5A-5B illustrate an exemplary striker tube for placement over adrill guide assembly;

FIG. 6 illustrates an exemplary depth gauge for determining the depth ofa pilot hole to be drilled for insertion of a screw for joint fusion;

FIG. 7A illustrates a side view of an exemplary cannulated drill bit andstop collar for drilling a pilot hole for insertion of a screw for jointfusion;

FIG. 7B illustrates a cross-section view of an exemplary cannulateddrill bit and stop collar for drilling a pilot hole for insertion of ascrew for joint fusion;

FIG. 7C illustrates a cross-section view of an exemplary stop collar;

FIG. 8 illustrates a cross-section view of an exemplary sacroiliac jointwith an applied guide pin, drill bit and drill guide;

FIG. 9 illustrates an exemplary driver for inserting a screw for jointfusion;

FIG. 10A illustrates a side view of an exemplary parallel spacerinstrument for placement of another guide pin;

FIG. 10B illustrates a side view of an exemplary parallel spacerinstrument for placement of another guide pin as placed on a drillguide;

FIG. 10C illustrates an exploded view of an exemplary parallel spacerinstrument;

FIG. 10D illustrates a perspective view of an exemplary parallel spacerinstrument;

FIG. 11A illustrates a perspective view of an exemplary packing plungerassembly placed in an exemplary plunger distance tool;

FIG. 11B illustrates an exemplary packing plunger assembly placed in adrill guide for packing a screw for joint fusion;

FIG. 12 illustrates an exemplary process for joint fusion; and

FIGS. 13A-F illustrate an exemplary process for fusion of a sacroiliacjoint.

DETAILED DESCRIPTION

Various embodiments or examples may be implemented in numerous ways,including as a system, a process or an apparatus. In general, operationsof disclosed processes may be performed in an arbitrary order, unlessotherwise provided in the claims. A detailed description of one or moreexamples is provided below along with accompanying figures. The detaileddescription is provided in connection with such examples, but is notlimited to any particular example. The scope is limited only by theclaims and numerous alternatives, modifications, and equivalents areencompassed. Numerous specific details are set forth in the followingdescription in order to provide a thorough understanding. These detailsare provided for the purpose of example and the described techniques maybe practiced according to the claims without some or all of thesespecific details. For clarity, technical material that is known in thetechnical fields related to the examples has not been described indetail to avoid unnecessarily obscuring the description.

Techniques for joint fusion are described, including systems,apparatuses and processes for fusing a joint. Systems and apparatusesfor fusing a joint include a screw (i.e., a cannulated screw), a drillguide assembly, a guide pin, a striker tube, a depth gauge, a cannulateddrill bit (e.g., an adjustable cannulated drill bit that employs a stopcollar), a driver, a parallel spacer instrument, a packing plungerassembly, and a plunger distance tool. As used herein, the term“cannulated” refers to having a cannula, or a hollow shaft. In someexamples, the screw may be inserted or implanted into tissue (e.g.,bone, cartilage, or other tissue in the joint). As used herein, the term“implant” or “implantation” refers to inserting or insertion into a partof a body. For example, a screw may be implanted into a joint (i.e., asacroiliac joint). In some examples, a screw may have a cannula in whichmaterials may be packed. Such materials may include osteogenic compounds(e.g., bone morphogenetic protein, or other osteogenic compounds thatmay ossify tissue in the joint), osteoconductive materials (e.g.,demineralized bone, hydroxyappatite, or other material that promotesbone growth), antibiotics, steroids, contrast materials, or othermaterials that may beneficial to fusing the joint, treating inflammationor other conditions in the joint, or enabling the visualization of thearea within and adjacent to an implanted screw. In some examples, thescrew may have slots, perforations, openings or orifices (collectively“slots”) along the wall of its shaft to allow the material packed insidethe cannula of the screw to contact (e.g., touch, seep into, affect,communicate with, or otherwise physically contact) tissue adjacent to,surrounding, or even within, the screw. In some examples, various toolsmay be used to insert a screw into a location on a joint, and to preparethe location for the insertion procedure. Such tools may include a drillguide assembly, which may comprise a drill guide and a pin sleeve; aguide pin; a striker tube; a depth gauge; a cannulated drill bit (e.g.,an adjustable cannulated drill bit with a stop collar); a driver; aparallel spacer instrument; a packing plunger assembly, which maycomprise a packing tube, a plunger and a loading port; a plungerdistance tool; and other tools.

In some examples, a guide pin may be inserted first into a joint at adesired location in a lateral position across the joint. In someexamples, a drill guide assembly may be used, along with the guide pin,to guide the preparation (i.e., drilling) of a pilot hole as well as toguide insertion of a cannulated screw or other implant. In someexamples, a cannulated drill bit may be used with the drill guide todrill the pilot hole. In some examples, a stop collar may be coupled tothe cannulated drill bit to assist with drilling the pilot hole to thedesired depth. In some examples, a driver or screwdriver may be used toinsert the screw into the pilot hole. The terms “driver” and“screwdriver” are used herein interchangeably to refer to a tool with atip configured to engage the head of a screw, the tool being useful forrotating a screw, or otherwise manipulating the screw, to drive thescrew into place in a joint. In some examples, a parallel spacerinstrument may be used to space another guide pin in preparation forinsertion of another screw. In some examples, a packing plunger assemblymay be used to pack the screw with the above-mentioned materials. Thepacking plunger may be used to pack materials into the screw either orboth pre- and post-insertion of the screw into the joint, and may beused with or without the drill guide assembly.

FIGS. 1A-1C illustrate a side view, a perspective view and across-section view, respectively, of an exemplary screw for jointfusion. Here, screw 100 includes head 102, tip 104, slots 106-108 and106 a-108 a, threads 112, shaft grooves 114 a-114 c and 116 a-116 c,head grooves 118 a-118 c, and tapered end 120. Like-numbered and namedelements in these views may describe the same or substantially similarelements. In some examples, screw 100 may be fabricated, manufactured,or otherwise formed, using various types of medical grade material,including stainless steel, plastic, composite materials, or alloys(e.g., Ti-6Al-4V ELI, another medical grade titanium alloy, or othermedical grade alloy) that may be corrosion resistant and biocompatible(i.e., not having a toxic or injurious effect on tissue into which it isimplanted). In some examples, threads 112 may be a helical ridge wrappedaround an outer surface of screw 100's shaft. In some examples, screw100 may be cannulated and may have a hollow shaft that extends from head102 to tip 104. Screw 100 may vary in length (e.g., ranging fromapproximately 25 mm to 50 mm, or longer or shorter) to accommodate sizeand geometric variance in a joint. Other dimensions of screw 100,including major and minor diameters of threads 112 (see, e.g., FIG. 3B),also may vary to accommodate size and geometric variance in a joint. Inone example, head 102 may be 9.5 mm in diameter and threads 112 may havea major diameter of 9 mm and a minor (i.e., root) diameter of 7.4 mm. Inother examples, head 102 may have a different diameter and threads 112may have different major and minor diameters. In some examples, an outersurface of screw 100's shaft may taper from head 102 to tapered end 120,and thus threads 112 also may taper (i.e., be a tapered thread) fromhead 102 to tapered end 120 (e.g., having a range of major and minordiameters from head 102 to tapered end 120). In some examples, thetapering of threads 112, as well as tapered end 120, may aid in guidingthe screw through a pilot hole. In other examples, head 102 and threads112 may be sized to fit within a tool or instrument, for example, adrill guide, as described below.

In some examples, screw 100's hollow shaft, or cannula, may be accessed(i.e., for packing material into) through an opening in head 102. Insome examples, head 102 may have a flat or partially flat surface (e.g.,pan-shaped with rounded edge, unevenly flat, or other partly flatsurface). In other examples, head 102 may have a different shape (e.g,dome, button, round, truss, mushroom, countersunk, oval, raised, bugle,cheese, fillister, flanged, or other screw head shape). In someexamples, the opening in head 102 may have a TORX® or TORX®-like shape(i.e., six-point or six-lobed shape) (see FIG. 3A) configured to receivethe tip of a TORX® or TORX®-like screwdriver (e.g., driver 902). Forexample, screw 100 may include head grooves 118 a-118 c, which may startat head 102 and extend linearly into the cannula of screw 100 to receivecomplementary lobes on the end of a screwdriver. For a TORX® orTORX®-like opening there may be six (6) total head grooves, includingfor example head grooves 118 a-118 c, to receive the complementary lobeson the tip of a TORX® or TORX®-like driver. In some examples, as shownin FIG. 1C, the opening in head 102 may be contiguous with, and form atop end of, screw 100's cannula. For example, the opening may provideaccess to the cannula, for example, to pack material into the screw.

As described herein, such materials may include osteogenic compounds(e.g., bone morphogenetic protein, or other osteogenic compounds thatmay ossify tissue), osteoconductive materials (e.g., demineralized bone,hydroxyappatite, or other material that promotes bone growth),antibiotics, steroids, contrast materials, or other materials that maybeneficial to fusing the joint, treating inflammation or otherconditions in the joint, or enabling the visualization of the areawithin and adjacent to the screw. For example, an osteogenic compound,such as bone morphogenetic protein or other compounds, may be packedinto screw 100's cannula such that, when screw 100 is inserted into ajoint or traverses through a joint (e.g., a sacroiliac joint), theosteogenic compound, for example through holes or openings (e.g., slots106-108 and 106 a-108 a) may come into contact with tissue in the jointadjacent to or surrounding screw 100, and ossify the tissue to fuse thejoint across and through the screw. In some examples, the osteogeniccompound may enter the joint and may fill the joint, partially orentirely. In other examples, an osteoconductive materials, such asdemineralized bone or hydroxyappatite or other materials, may be packedinto screw 100's cannula such that, when screw 100 is inserted into ajoint, the osteoconductive material may come into contact with tissue inthe joint adjacent to or surrounding screw 100, for example throughslots 106-108 and 106 a-108 a, and promote bone growth into the screwand the joint to fuse the joint across and through the screw. In stillother examples, a substance for treating sacroiliitis, such as steroidsor antibiotics or other substances, may be packed into screw 100'scannula such that, when screw 100 is inserted into the joint, thesubstance may come into contact with tissue in the joint adjacent to orsurrounding screw 100, for example through slots 106-108 and 106 a-108a, and treat the inflamed joint tissue. In yet other examples, acontrast material may be packed into screw 100's cannula such that, whenscrew 100 is inserted into the joint, the contrast material within screw100, and in some examples absorbed by tissue adjacent to or surroundingscrew 100, may be viewed using visualization techniques (e.g., x-ray,fluoroscope, ultrasound, or other visualization technique). In stillother examples, different materials may be packed into screw 100 fordifferent purposes. In yet other examples, the above-described materialsmay also come into contact with tissue adjacent to, or surrounding,screw 100 through an opening at tip 104. As described herein, screw 100may be packed with material prior to being inserted into the joint, andmay also be packed after insertion into the joint. Also as describedherein, such materials may be packed into screw 100 using a packingplunger assembly (see, e.g., FIGS. 11A-11B).

In some examples, slots 106-108 and 106 a-108 a may provide openings inscrew 100's shaft to enable material packed inside screw 100 to comeinto contact with surrounding or adjacent tissue (e.g., bone, cartilage,or other tissue in the joint) when screw 100 is implanted. In someexamples, slots 106-108 and 106 a-108 a may be substantially oval,substantially elliptical, or capsule-shaped (i.e., substantially ovalwith two parallel sides and two semicircular ends). In other examples,slots 106-108 and 106 a-108 a may be shaped differently (e.g., circular,rectangular, rounded rectangular, squared or other shapes). In someexamples, there may be two or more slots or openings (e.g., slots106-108) linearly aligned from head 102 to tapered end 120, as shown,along a side of the shaft of screw 100. In some examples, slots 106-108may be connected to each other and to head 102 and tapered end 120 bylinear grooves (e.g., shaft grooves 114 a-114 c). In some examples,another set of two or more openings (e.g., slots 106 a-108 a) withconnecting shaft grooves (e.g., shaft grooves 116 a-116 c) may berepeated along another side of the shaft of screw 100. For example,slots 106 a-108 a and shaft grooves 116 a-116 c may be disposed linearlyfrom head 102 to tapered end 120 along a side of the shaft of screw 100approximately ninety degrees (90°) from slots 106-108 and shaft grooves114 a-114 c, as shown.

In some examples, tip 104 may be disposed on tapered end 120. In someexamples, tip 104 may provide another opening for material packed insidethe shaft to come into contact with surrounding or adjacent tissue. Insome examples, this opening may be circular, with the same or similardiameter as the cannula of screw 100. In other examples, the opening maybe smaller in diameter than the cannula of screw 100 (see FIG. 1C). Insome examples, as shown in FIG. 1C, the opening in tip 104 may becontiguous with, and form an end of, screw 100's cannula. In someexamples, tapered end 120 may aid in guiding screw 100 into a pilothole.

In some examples, openings in screw 100, including slots 106-108 and 106a-108 a, and tip 104, may enable screw 100 to deliver materials to boneand other joint tissue adjacent to, or surrounding, screw 100, forexample, to regenerate bone or treat inflammation, infection, or otherailments, in the joint. For example, screw 100 may have a cannula inwhich such materials may be packed, as described herein. After beingpacked, screw 100 may be implanted (i.e., inserted) into or across ajoint, and such materials may be delivered from screw 100 through slots106-108 and 106 a-108 a, or other openings (e.g., in head 102 or tip 104of screw 100) and to a joint. In some examples, the above-describedmaterials may enter a joint through slots 106-108 and 106 a-108 a. Insome examples, the above-described materials may fill a joint, partiallyor entirely, after entering the joint through slots 106-108 and 106a-108 a.

In some examples, screws 100 and 200 may be configured to fit or slidewithin a drill guide (e.g., drill guide 404) and over a guide pin (e.g.,guide pin 418) for implantation (e.g., according to processes 1200 and1300). In other examples, screws 100 and 200 may be formed differentlyand are not limited to the examples described.

FIGS. 2A-2B illustrate a side view and a perspective view, respectively,of an alternative exemplary screw for joint fusion. Here, screw 200includes head 202, tip 204, slots 206-210 and 206 a-210 a, threads 212,shaft grooves 214 a-214 d and 216 a-216 d, and tapered end 220.Like-numbered and named elements in these views may describe the same orsubstantially similar elements above. For example, like-named elementsin FIGS. 2A-2B may describe the same or substantially similar elementsin FIGS. 1A-1C. In some examples, screw 200 may include three slots(e.g., slots 206-210 or 206 a-210 a) disposed linearly (i.e., in a linefrom head 202 to tapered end 220) along one or more sides of screw 200.For example, slots 206-210 may be disposed linearly along one side ofscrew 200, and slots 206 a-210 a may be disposed linearly along anotherside approximately ninety degrees (90°) from slots 206-210.

In some examples, openings in screw 200, including slots 206-210 and 206a-210 a, and tip 204, may enable screw 200 to deliver materials to boneand other joint tissue adjacent to, or surrounding, screw 200, forexample, to regenerate bone or treat inflammation, infection, or otherailments, in the joint. For example, screw 200 may have a cannula inwhich such materials may be packed, as described herein. After beingpacked, screw 200 may be implanted (i.e., inserted) into or across ajoint, and such materials may be delivered from screw 200 through slots206-210 and 206 a-210 a, or other openings (e.g., in head 202 or tip 204of screw 100) and to a joint. In some examples, the above-describedmaterials may enter a joint through slots 206-210 and 206 a-210 a. Insome examples, the above-described materials may fill a joint, partiallyor entirely, after entering the joint through slots 206-210 and 206a-210 a.

FIG. 3A illustrates a top view of an exemplary screw for joint fusion.Here, top view 222 includes head 202, shaft 224, openings 226-228, headgrooves 218 a-218 f and head diameter 230. Like-numbered and namedelements in these views may describe the same or substantially similarelements above. For example, like-named elements in FIG. 3A may describethe same or substantially similar elements in FIGS. 1A-1C & FIGS. 2A-2B.In some examples, head 202 may be circular with head diameter 230. Insome examples, head diameter 230 may correspond to the diameter of acannula of a drill guide (e.g., drill guide 404). In other examples,head 202 may be shaped differently (e.g., triangular, hexagonal, orother shapes not shown). In some examples, opening 226 may be disposedat head 202, and opening 228 may be disposed at tip 204 (see, e.g.,FIGS. 2A-2B and 3B). In some examples, the diameters of openings 226 and228 may be the same or similar. In other examples, the diameter ofopenings 226 may be different from the diameter of opening 228. In someexamples, opening 226 may include head grooves 218 a-218 f to acceptcorresponding lobes of a TORX® or TORX®-like driver (i.e., having sixlobes). As shown, head grooves 218 a-218 f may be semi-circular inshape. In other examples, head grooves 218 a-218 f may be shapeddifferently (e.g., with points, edges, or other shapes). In otherexamples, opening 228 may be configured to accept a different type ofdriver. For example, opening 228 may include more or fewer head groovesthat may be shaped the same or differently.

In some examples, cannula 224 may extend uninterrupted from head 202 totip 204 (see FIGS. 2A-2B and 3B). In some examples, cannula 224 may beconfigured to fit over a guide pin, as described herein. In someexamples, cannula 224 also may be configured to receive and holdmaterial (e.g., osteogenic compounds, osteoconductive materials,antibiotics, steroids, contrast materials, or other materials that maybeneficial to fusing the joint, treating inflammation or otherconditions in the joint, or enabling the visualization of the areawithin and adjacent to the screw, as described herein).

FIG. 3B illustrates a bottom view of an exemplary screw for jointfusion. Here, bottom view 230 includes tip 204, slots 206-210, 206 a-210a, 206 b-210 b and 206 c-210 c, tapered end 220, cannula 224, opening228, head diameter 230 and major diameter 232. Like-numbered and namedelements in these views may describe the same or substantially similarelements above. For example, like-named elements in FIG. 3B may describethe same or substantially similar elements in FIGS. 1A-1C, FIGS. 2A-2Band FIG. 3A. In some examples, opening 228 may be disposed at tip 204and the end of cannula 224. In some examples, head diameter 230 may belarger than major diameter 232, and major diameter 232 in turn may belarger than a minor (i.e., root) diameter (not shown). In some examples,a plurality of slots (e.g., slots 206-210, 206 a-210 a, 206 b-210 b and206 c-210 c) may be disposed along the walls of cannula 224. In someexamples, a first set of three (3) slots (e.g., slots 206-210) may bedisposed linearly from head 202 (see FIGS. 2A-2B and 3A) to tip 204along the wall of cannula 224. In some examples, second, third andfourth sets of slots (e.g., slots 206 a-210 a, 206 b-210 b and 206 c-210c) may be disposed, also linearly from head 202 to tapered end 220,along the wall of cannula 224 at approximately ninety degree (90°)intervals. In other examples, a screw may have more or fewer sets oflinearly disposed slots. In still other examples, each set of linearlydisposed slots may include more or fewer slots. In yet other examples,each set of slots may be disposed at greater or lesser intervals.

FIG. 4A illustrates an exemplary drill guide assembly having a pinsleeve and a drill guide. Here, drill guide assembly 400 may include pinsleeve 402 and drill guide 404. In some examples, pin sleeve 402 furthermay include pin sleeve head 406, pin sleeve threads 408, and pin sleevetip 410. In some examples, drill guide 404 may include handle 412, drillguide head 414, and drill guide tip 416. In some examples, pin sleeve402 has a hollow shaft that fits more closely over a guide pin thandrill guide 404. In some examples, the outer diameter of pin sleeve402's shaft is shaped to fit inside the cannula of drill guide 404,which has an internal diameter that may be configured to accommodatetools and implants (e.g., screws 100 and 200, and the like) having alarger diameter than a guide pin. For example, the diameter of drillguide 404's cannula may correspond to (i.e., be sized to fit) the heador outer diameter on an implant (e.g., screws 100 and 200). In someexamples, the internal surface of drill guide 404 may be configured toguide an implant inserted into drill guide 404 from drill guide head 414to drill guide tip 416 (e.g., using a groove, an indentation, notch,channel, or the like (not shown) configured to receive a guide point,protrusion, or other structure on an implant (e.g., screws 100 and200)). In some examples, drill guide head 414 may have threads (notshown) complementary to, and configured to receive, threads 408 on pinsleeve 402. For example, pin sleeve 402 may be inserted into drill guide404, and they may be screwed together at threads 408 and drill guidehead 414 by holding and turning pin sleeve head 406. In some examples,handle 412 may extend from an outer surface of drill guide head 414. Insome examples, handle 412 may be used to hold drill guide 404, and othertools and implants that may be coupled to or placed within drill guide404, in place during an implantation process. In some examples, drillguide tip 416 may have spikes, teeth, wedges, or other structures, toengage a bone. In some examples, guide pin tip 410 may form a trocar forintroducing drill guide assembly 400 into a bone.

FIG. 4B illustrates an exemplary drill guide assembly placed over aguide pin. Here, diagram 420 may include drill guide 404, pin sleevehead 406 (of pin sleeve 402), threads 408 (of pin sleeve 402), handle412, drill guide head 414, drill guide tip 416 and guide pin 418.Like-numbered and named elements in this view may describe the same orsubstantially similar elements as in previous views (e.g., FIG. 4A). Insome examples, guide pin 418 may be a medical grade sterile metal pin(e.g., Kirschner wire, Steinmann pin, or other metal pin) suitable foruse in medical procedures. In some examples, guide pin 418 may be usedfor alignment and guidance of a drill guide (e.g., drill guide 404), animplant (e.g., a screw or other implant), and other tools. As shown,drill guide tip 416 is engaged with an ilium (i.e., its spikes, teeth,wedges or other structure for engaging a bone, are embedded in theilium). In other examples, drill guide assembly 400 may be formeddifferently and is not limited to the examples described.

FIGS. 5A-5B illustrate an exemplary striker tube for placement over adrill guide assembly. Here, diagrams 500 and 520 show striker tube 502,striker tube head 504, striker tube cannula 506, edge 508, drill guide404, pin sleeve head 406, threads 408, handle 412, drill guide head 414,drill guide tip 416 and guide pin 418. Like-numbered and named elementsin this view may describe the same or substantially similar elements asin previous views (e.g., FIGS. 4A-4B). In some examples, striker tube502 may include striker tube head 504, striker tube cannula 506 and edge508. In some examples, striker tube head 504 may have a flat surface,and may be configured to receive strikes from a flat surface of amallet. In some examples, striker tube cannula 506 may be shaped to fitover the portions of guide pin 418, pin sleeve head 406 and threads 408that protrude from drill guide head 414. In some examples, edge 508 maybe shaped to fit over drill guide head 414. In some examples, strikertube 502 may push drill guide 404 when stricken with a mallet, causingdrill guide 404 to engage a bone. In other examples, striker tube 502may be formed differently and is not limited to the examples described.

FIG. 6 illustrates an exemplary depth gauge for determining the depth ofa pilot hole to be drilled for insertion of a screw for joint fusion.Here, diagram 600 includes depth gauge 602, depth markings 604 a-604 b,guide pin receiving element 606, drill guide contact marking 608, drillguide 404, handle 412, drill guide head 414, and guide pin 418.Like-numbered and named elements in this view may describe the same orsubstantially similar elements as in previous views (e.g., FIGS. 4A-4B &5A-5B). In some examples, depth gauge 602 may be configured to determinethe depth in which guide pin 418 is inserted into a bone and/or joint.In some examples, drill guide contact marking 608 may indicate the edgeor side of depth gauge 602 that is to be placed onto drill guide 404(i.e., at drill guide head 414). In some examples, depth gauge 602 mayinclude depth markings 604 a-604 b, which account for the lengths ofdrill guide 404 and guide pin 418, such that when depth gauge 602 isplaced over guide pin 418 until drill guide contact marking 608 contacts(i.e., rests against) drill guide head 414, the depth markings 604 a-604b may indicate the depth that guide pin 418 has been inserted into abone or joint. For example, where guide pin 418 is approximately 229 mmlong, and drill guide 404 is approximately 140 mm from head 414 to tip416 (shown in FIGS. 4A-5A), the marking for a 40 mm depth of guide pin418 may be approximately 48 mm from the edge indicated by drill guidecontact marking 608.

In some examples, depth gauge 602 includes guide pin receiving element606, which is configured to slide over guide pin 418. In some examples,depth markings 604 a-604 b comprise a set of markings and numbersindicating a range of depths of guide pin 418. In some examples, depthmarkings 604 a-604 b may indicate a range of 25-50 mm depths. In otherexamples, depth gauge 602 may have different depth markings, and thusindicate a different range of depths. In an example, guide pin receivingelement 606 may slide over guide pin 418 until drill guide contactmarking 608 comes into contact with drill guide head 414. The number indepth markings 604 a-604 b that corresponds to the location of the endof guide pin 418 may indicate the depth of guide pin 418. In otherexamples, depth markings 604 a-604 b may indicate a different depth thatmay correspond and be calibrated to the depth of guide pin 418 (e.g.,depth markings 604 a-604 b may indicate a desired drilling depth for apilot hole, a depth of a screw to be implanted, or other depth that isassociated with the depth of guide pin 418, and may thus be measuredagainst the depth of guide pin 418). In still other examples, depthgauge 602 may include more or fewer elements and is not limited to theexamples described.

FIG. 7A illustrates a side view of an exemplary cannulated drill bit andstop collar for drilling a pilot hole for insertion of a screw for jointfusion. Here, cannulated drill bit 700 may include cutting tip 702,shank 704, adjustment ridges 706, depth markings 708, and may be fittedwith stop collar 710, which includes stop collar edge 718. As usedherein, “drill bit” refers to any cutting tool configured to createcylindrical holes, and “shank” refers to an end of the drill bit,usually the end opposite the cutting tip, configured to be grasped by achuck of a drill. In some examples, cannulated drill bit 700 may beconfigured to drill a pilot hole to a predetermined depth. For example,cutting tip 702 may be configured to cut cylindrical holes into a boneand/or joint when torque and axial force is applied to rotate cuttingtip 702 (i.e., by a drill). In some examples, cannulated drill bit 700may be adjustable, and thereby configured to drill a range of depthsusing depth markings 708 and the placement of stop collar 710 overadjustment ridges 706 to configure cannulated drill bit 700 to stopdrilling at a desired drilling depth. In some examples, stop collar 710may stop cannulated drill bit 700 from continuing to drill when stopcollar edge 718 meets a drill guide head (e.g., drill guide head 414).In this example, the outside diameter of cannulated drill bit 700 may beconfigured to fit within a drill guide (e.g., drill guide 404), whereasthe outside diameter of stop collar edge 718 is larger than the diameterof a drill guide's cannula, and thus stop collar 710 may not fit withina drill guide.

In some examples, a desired drilling depth (i.e., depth of a pilot hole)may be the same or similar to the depth of a guide pin that has beeninserted into a bone and/or joint. In other examples, the desireddrilling depth may be offset (i.e., less deep) by a predetermined amount(e.g., a few millimeters or other offset amount). For example, if aguide pin has been inserted 40 mm deep into the sacroiliac joint, acorresponding desired drilling depth for the pilot hole may be 40 mm, orit may be 40 mm minus the predetermined offset may be selected (i.e., ifthe predetermined offset is 3 mm, then the desired drilling depth inthis example would be 37 mm) (see FIG. 8).

In some examples, cannulated drill bit 700 may be configured for usewith depth gauge 602, and depth markings 708 may correspond to depthmarkings 604 a-604 b. For example, if depth gauge 602 has been used todetermine that a guide pin (i.e., guide pin 418) has been inserted 40 mmdeep into a bone and/or joint, depth markings 708 may include a “40 mm”mark that corresponds to the 40 mm marking on depth gauge 602, whereinthe fitting of stop collar 710 onto cannulated drill bit 700 and at the40 mm marking on cannulated drill bit 700 may guide cannulated drill bit700 to drill up to, and not beyond, a desired drilling depthcorresponding to the 40 mm depth of the guide pin. In this example, ifthe desired drilling depth is to be the same as the depth of the guidepin, then fitting stop collar 710 onto cannulated drill bit 700 and atthe 40 mm marking on cannulated drill bit 700 may stop cannulated drillbit 700 (i.e., when stop collar edge 718 meets drill guide head 414 (notshown)) when the pilot hole is at 40 mm. In another example, if thedesired drilling depth is to be offset from the depth of the guide pinby 3 mm, then fitting stop collar 710 onto cannulated drill bit 700 andat the 40 mm marking on cannulated drill bit 700 may stop cannulateddrill bit 700 (i.e., when stop collar edge 718 meets drill guide head414 (not shown)) when the pilot hole is at 37 mm (see FIG. 8).

FIG. 7B illustrates a cross-section view of an exemplary cannulateddrill bit and stop collar for drilling a pilot hole for insertion of ascrew for joint fusion. Here, cannulated drill bit 700 includesadjustment ridges 706, cannula 714, and may be fitted with stop collar710, which may include stop collar ridge 712. In some examples, cannula714 may be configured (i.e., sized) to fit over a guide pin (e.g., guidepin 418). FIG. 7C illustrates a cross-section view of an exemplary stopcollar, which shows stop collar 710, including stop collar ridge 712 andstop collar cannula 716. In some examples, cannulated drill bit 700 maybe configured to fit into cannula 716. In some examples, stop collarridge 712 may engage adjustment ridges 706 when stop collar 710 isplaced over cannulated drill bit 700 and twisted or turned. In someexamples, stop collar ridge 712 may engage adjustment ridges 706 bysliding in between a set of two of adjustment ridges 706 when stopcollar 710 is turned. In other examples, cannulated drill bit 700 andstop collar 710 may be formed differently and are not limited to theexamples described.

FIG. 8 illustrates a cross-section view of an exemplary sacroiliac jointwith an applied guide pin, drill bit and drill guide. Here, diagram 800includes drill guide 404, drill guide tip 416, guide pin 418, andcannulated drill bit 700 with cutting tip 702. Like-numbered and namedelements in this view may describe the same or substantially similarelements as in previous views (e.g., FIGS. 4A-4B, 5A-5B, 6 & 7A-7C). Insome examples, drill guide 404 may engage an ilium using drill guide tip416, as described herein. In some examples, drill guide 404 may comprisea cannula or hollow shaft configured to fit over various tools for usein inserting an implant into a bone and/or joint (e.g., pin sleeve 402,cannulated drill bit 700, driver 902, packing tube 1102, or othertools), which may in turn be configured to fit over (i.e., slide onto) aguide pin. For example, cannulated drill bit 700 may be configured tofit or slide into drill guide 404 and over guide pin 418. In someexamples, cannulated drill bit 700 may be configured to drill a pilothole depth that is offset from the depth of the guide pin (e.g., guidepin 418) by a predetermined distance, such that cutting tip 702 may stopa predetermined distance before reaching the end of guide pin 418.

FIG. 9 illustrates an exemplary driver for inserting a screw for jointfusion. Here, diagram 900 includes driver 902, mating tip 904, driverhandle 906, drill guide 404, handle 412, and drill guide head 414.Like-numbered and named elements in this view may describe the same orsubstantially similar elements as in previous views (e.g., FIGS. 4A-4B,5A-5B, 6, 7A-7C & 8). In some examples, driver 902 may be configured todrive a screw (e.g., screws 100 and 200) into a bone and/or joint. Insome examples, driver 902 may have a shaft configured to fit or slidewithin drill guide 404. In some examples, mating tip 904 may be shapedto engage (i.e., fit) a head of a screw (e.g., heads 102 and 202). Forexample, driver 902 may be a TORX® driver and mating tip 904 may beshaped to fit a TORX® head screw (e.g., with a six-point or six-lobedshape). In other examples, mating tip 904 may be shaped differently toengage different types of screws (e.g., PHILLIPS™ (i.e., having acruciform or cross shape with four lobes), slot, flat, Robertson, hex,or other type of screws). In some examples, driver handle 906 may beused to turn driver 902, and consequently turn a screw engaged by matingtip 904. In some examples, driver 902 may be a manual driver. In otherexamples, driver 902 may be powered (i.e., electrically). In someexamples, driver 902 also may be ratcheting or torque-limited. In someexamples, driver handle 906 may be formed separately from driver 902'sshaft and driver tip 904. In some examples, handle 906 may be configuredto be removably coupled with various types of drivers (e.g., TORX®,PHILLIPS™, slot, flat, Robertson, hex, or other types of screwdrivers).In other examples, driver 902 and driver handle 906 may be formeddifferently, and are not limited to the examples shown and described.

FIG. 10A illustrates a side view of an exemplary parallel spacerinstrument for placement of another guide pin. Here, parallel spacerinstrument 1000 includes parallel spacer block 1002, drill guide tube1004, sliding block 1006, guide pin tube 1008 and locking nut 1010.Like-numbered and named elements in this view may describe the same orsubstantially similar elements as in previous views (e.g., FIGS. 4A-4B,5A-5B, 6, 7A-7C, 8 & 9). In some examples, parallel spacer instrument1000 may be configured to place another or a next guide pin at adistance from a previously placed implant (i.e., a previously implantedscrew). In some examples, drill guide tube 1004 may be integrally formedwith parallel spacer block 1002. In some examples, guide pin tube 1008may be integrally formed with sliding block 1006. In some examples,sliding block 1006 may fit within an opening in, and be adjustablycoupled to, parallel spacer block 1002 (see, e.g., FIGS. 10C-10D). Forexample, sliding block 1006 may be coupled to parallel spacer block 1002in a manner that enables sliding block 1006 to slide horizontally alongan opening in parallel spacer block 1002 (see, e.g., FIGS. 10C-10D). Insome examples, locking nut 1010 may be used to secure sliding block 1006to parallel spacer block 1002.

In some examples, drill guide tube 1004 may be sized (i.e., have anouter diameter configured) to fit within the cannula of a drill guide,and also may have its own hollow shaft (i.e., a drill guide tubecannula) configured to fit around or over a guide pin, as shown in FIG.10B. FIG. 10B illustrates a side view of an exemplary parallel spacerinstrument for placement of another guide pin as placed on a drillguide. Here, diagram 1020 includes, parallel spacer block 2002, drillguide tube 1004, sliding block 1006, guide pin tube 1008, locking nut1010, threads 1012, drill guide 404, handle 412, drill guide head 414,drill guide tip 416 and guide pin 418. Like-numbered and named elementsin this view may describe the same or substantially similar elements asin previous views (e.g., FIGS. 4A-4B, 5A-5B, 6, 7A-7C, 8, 9 & 10A). Asshown, drill guide tube 1004 may fit into drill guide 404, with part ofparallel spacer block resting against drill guide head 414. Also asshown, drill guide tip 416 may have spikes, teeth, wedges, or otherstructures configured to assist drill guide 404 with engaging a bone. Insome examples, guide pin 418 may still be in place within drill guide404, in which case drill guide tube 1004 may fit over guide pin 418. Insome examples, once parallel spacer instrument 1000 is placed on drillguide 404, a next guide pin (not shown) may be inserted through guidepin tube 1008 until the end of the next guide pin rests against a bone(i.e., an ilium). While in place in guide pin tube 1008, the next guidepin may be advanced into the bone and through a joint to a desired depthusing a mallet.

FIG. 10C illustrates an exploded view of an exemplary parallel spacerinstrument; and FIG. 10D illustrates a perspective view of an exemplaryparallel spacer instrument. Here, parallel spacer instrument 1000includes parallel spacer block 1002, opening 1026, spacer markings 1024,drill guide tube 1004, drill guide tube cannula 1022, sliding block1006, leading edge 1028, guide pin tube 1008, guide pin tube cannula1030, locking nut 1010, and threads 1012. Like-numbered and namedelements in this view may describe the same or substantially similarelements as in previous views (e.g., FIGS. 4A-4B, 5A-5B, 6, 7A-7C, 8, 9& 10A-10B). In some examples, parallel spacer block may include opening1026 for receiving sliding block 1006. Opening 1026 may be sized toallow sliding block 1006 to slide horizontally within parallel spacerblock 1002. In some examples, parallel spacer block 1002 may comprisespacer markings 1024 with numerical labels for measuring out the spacingbetween implants. In some examples, when leading edge 1028 is placed atone of spacer markings 1024, the number corresponding to that markingmay indicate the space (i.e., distance, for example, in millimeters)between a previously placed implant, as placed by a drill guide (e.g.,drill guide 404) within which drill guide tube 1004 is inserted, and aguide pin placed in guide pin tube 1004 (i.e., the next guide pin).This, in turn, may determine the spacing between an implant and a nextimplant. In some examples, drill guide tube cannula 1022 and guide pintube cannula 1030 each may be configured (e.g., have a diameter fit, orbe sized) to receive a guide pin. In some examples, guide tube cannula1022 and guide pin tube cannula 1030 may have the same diameter.

In some examples, sliding block 1006 may slide horizontally withinopening 1026 until leading edge 1028 reaches a marking corresponding toa desired spacing for a next implant. Once sliding block 1006 is at thedesired setting, locking nut 1010 may be used to tighten or securelycouple sliding block 1006 to parallel spacer block 1002 such thatsliding block 1006 stops sliding within opening 1026. For example,locking nut 1010 may be tightened by screwing locking nut 1010 ontothreads 1012. In some examples, sliding block 1006 may be reset to adifferent spacing at a later time by unscrewing locking nut 1010 toloosen or release sliding block 1006 from parallel spacer block 1002. Inother examples, parallel spacer instrument 1000 may be formeddifferently and is not limited to the examples shown and described.

FIG. 11A illustrates a perspective view of an exemplary packing plungerassembly placed in an exemplary plunger distance tool; and FIG. 11Billustrates an exemplary packing plunger assembly placed in a drillguide for packing a screw for joint fusion. Here, diagrams 1100 and 1120include packing plunger assembly 1102, packing tube 1104, plunger 1106,loading port 1108, plunger distance tool 1110, plunger distance markings1112, one or more plunger wells 1114, drill guide 404, handle 412, anddrill guide head 414. Like-numbered and named elements in this view maydescribe the same or substantially similar elements as in previous views(e.g., FIGS. 4A-4B, 5A-5B, 6, 7A-7C, 8 & 9). In some examples, packingplunger assembly 1102 may comprise packing tube 1104, plunger 1106 andloading port 1108. In some examples, packing tube 1104 may be coupled toplunger 1106 with a portion of plunger 1106 inserted into packing tube1104 to form packing plunger assembly 1102. In some examples, packingtube 1104 and plunger 1106 may be coupled such that plunger 1106 has aplunger shaft configured to be inserted into a hollow internal space(i.e., cannula) inside packing tube 1104, the plunger shaft of plunger1106 fitting into packing tube 1104 such that pushing (i.e., depressing)plunger 1106 acts to modify the internal volume of packing tube 1104(e.g., plunger shaft of plunger 1106 has a diameter that fits withinpacking tube 1104's cannula such that an exterior surface of plunger1106's shaft contacts an interior surface of packing tube 1104, orplunger 1106 fits within packing tube 1104 such that an exterior surfaceof plunger 1106 creates a seal with an internal surface of packing tube1104, or the like). For example, plunger 1106 may be moved in and out ofan end of packing tube 1104 to draw into, and dispense out from, packingtube 1104 various materials (e.g., liquids, gases, gels, or othermaterials, as described herein), for example, through loading port 1108.In some examples, loading port 1108 may be disposed at an end of packingtube 1104, which may be opposite another end of packing tube 1104 inwhich a plunger shaft of plunger 1106 may be inserted. In some examples,loading port 1108 may comprise an opening between a cannula withinpacking tube 1104 and an environment outside of packing tube 1104. Asdescribed herein, such materials may include osteogenic compounds (e.g.,bone morphogenetic protein, or other osteogenic compounds that mayossify tissue in the joint), osteoconductive materials (e.g.,demineralized bone, hydroxyappatite, or other material that promotesbone growth), antibiotics, steroids, contrast materials, or othermaterials that may beneficial to fusing the joint, treating inflammationor other conditions in the joint, or enabling the visualization of thearea within and adjacent to the screw. In some examples, packing tube1104 may be filled with an amount of one or more of these materials tobe packed into an implant (e.g., screws 100 and 200), as describedherein. In some examples, packing tube 1104 may be filled using loadingport 1108 (e.g., material may be drawn into packing tube 1104 throughloading port 1108, material may be pushed or otherwise dispensed intopacking tube 1104 through loading port 1108, or other loading methodsmay be employed). In some examples, plunger 1106 may be depressed todispense material from packing tube 1104 out through loading port 1108,for example, into a cannulated screw (e.g., screws 100 and 200), whichmay in turn deliver said material into a joint, as described above,through openings (e.g., slots 106-108, 106 a-108 a, 206-210, and 206a-210 a, or the like) disposed on the shaft of said cannulated screw(e.g., screws 100 and 200, or the like), or through other openings(e.g., in head 102, head 202, tip 104 and tip 204, or the like).

In some examples, plunger distance tool 1110 may include bed 1116,plunger distance markings 1112 and corresponding plunger wells 1114. Forexample, plunger wells 1114 may be shaped to receive the head of plunger1106. In some examples, plunger distance tool 1110 may be used todetermine a position of plunger 1106 corresponding to the size ofimplant to be packed. For example, as shown in FIG. 11A, when the headof plunger 1106, with plunger 1106 coupled to packing tube 1104 isplaced into the one of plunger wells 1114 corresponding to the “40” or40 mm plunger distance marking and packing tube 1104 is placed onto bed1116, this sets packing plunger assembly 1102 to have an internal volumebe filled with an amount of material appropriate for packing a 40 mmscrew, as described herein.

In some examples, loading port 1108 may be configured to fit onto, orengage, the head of a cannulated screw (e.g., screws 100 and 200). Forexample, loading port 1108 may have an opening disposed on the end of atubular protrusion sized to fit within an opening in the top of acannulated screw. Once loading port 1108 is engaged with the head of acannulated screw, plunger 1106 may be depressed to dispense materialfrom packing tube 1104, out through an opening at an end of loading port1108, and into a cannulated screw (e.g., screws 100 and 200), which mayin turn deliver said material into a joint, as described above.

In some examples, packing plunger assembly 1102 may be used with a drillguide (e.g., drill guide 404) to pack an implanted screw with material,as shown in FIG. 11B. In other examples, packing plunger assembly 1102may be used without a drill guide to pack a screw, for example, beforeimplantation of the screw. In yet other examples, packing plungerassembly 1102 may be used without a drill guide to pack a previouslyimplanted screw. In still other examples, packing plunger assembly 1102may be formed differently and is not limited to the examples described.

FIG. 12 illustrates an exemplary process for joint fusion. Here, process1200 begins with obtaining a visual image of an area of tissuesurrounding a location in which to insert a screw (1202). In someexamples, the obtaining the visual image may include performing lateraland anteroposterior (AP) radiographs, using fluoroscopy units to obtainvarious lateral and AP views (e.g., Ferguson's view, or other views), orusing other x-ray or other imaging techniques. After the visual image isobtained, the visual image may be examined to confirm a pathology andidentify the location in which to insert the screw (1204). The pathologymay be a diagnosis (e.g., joint disruption, joint inflammation (e.g.,degenerative sacroiliitis), or other diagnosis) determined from priortesting and imaging of the joint area. In some examples, identifying alocation in which to insert the screw may include identifying surgicallandmarks. In some examples, identifying a location in which to insertthe screw also may include determining a position and trajectory forinserting a guide pin and a screw. Once a location is identified forinserting a screw, an incision may be created in the area of tissuesurrounding the location (1206). In some examples, the incision may beapproximately 2-3 cm long. In other examples, the length and location ofthe incision may vary depending on the size, dimensions, compositionand/or geometry of the area of tissue, as may be sufficient foraccessing a bone in the joint. For example, the length and placement ofthe incision may be different for a more obese patient (i.e., moreposterior) than for a less obese patient. In some examples, the jointmay be the sacroiliac joint, and the bone may be the ilium.

Once an incision is created, the area of tissue surrounding the locationmay be prepared for insertion of the screw, including placing a guidepin in the location, the guide pin configured to assist with placementof a drill guide, engaging a bone in the location with the drill guide,and drilling a pilot hole into the bone and an adjacent bone using thedrill guide (1208). In some examples, the preparation of the area oftissue may also include separating the tissue at the incision to accessthe bone (i.e., the ilium). In some examples, the guide pin may be amedical grade sterile metal pin (e.g., Kirschner wire, Steinmann pin, orother metal pin) suitable for use in medical procedures. In someexamples, placing a guide pin in the location may include aligning theguide pin (i.e., with the previously determined trajectory) andadvancing the guide pin through a bone (i.e., the ilium), a joint (i.e.,sacroiliac joint) and into an adjacent bone (i.e., sacrum) using amallet. The guide pin should not touch, puncture, violate, or otherwiseinterfere with nerves and other sensitive or vulnerable tissuesurrounding or adjacent to the joint (e.g., spinal canal, neuroforamen,anterior sacral cortical wall, sacral ala, or other tissue).

In some examples, engaging a bone in the location with a drill guide mayinclude assembling a drill guide assembly having a pin sleeve and thedrill guide, the pin sleeve having a trocar tip and configured to slideinto the drill guide's cannula. In some examples, engaging a bone in thelocation with a drill guide also includes placing the drill guideassembly over the guide pin until the trocar tip rests against the bone.In some examples, engaging a bone in the location with a drill guidefurther includes unscrewing the pin sleeve while advancing the drillguide until the drill guide rests against the bone and the pin sleeve isbacked away from the bone. In some examples, engaging a bone in thelocation with a drill guide also includes installing a striker tube overthe pin sleeve and guide pin, onto the drill guide. In some examples,engaging a bone in the location with a drill guide further includestapping the striker tube until the drill guide engages the bone. Oncethe drill guide engages the bone, the striker tube and pin sleeve may beremoved.

In some examples, drilling a pilot hole into the bone (i.e., ilium) andan adjacent bone (i.e., sacrum) using the drill guide may includedetermining a drill depth using a drill depth gauge. In some examples,drilling a pilot hole into the bone and the adjacent bone also mayinclude placing a drill bit stop collar over a cannulated adjustabledrill bit according to the drill depth. In some examples, drilling apilot hole into the bone and the adjacent bone further may includeinserting the cannulated adjustable drill bit into the drill guide andover the guide pin. In some examples, drilling a pilot hole into thebone and the adjacent bone also may include drilling a hole through thebone, the joint and into the adjacent bone using the drill bit and adrill, the hole having the drill depth. Once the pilot hole is drilled,the drill and the cannulated adjustable drill bit may be removed.

Once the area of tissue is prepared for insertion of a screw, the screwmay be inserted into the bone (i.e., ilium), the adjacent bone (i.e.,sacrum) and a joint (i.e., sacroiliac joint) in between the bone and theadjacent bone, using the drill guide, including packing the screw with amaterial, inserting the screw into the drill guide, inserting a driverinto the drill guide to engage the screw, and threading the screw intothe pilot hole until the screw's head stops against the bone (1210). Theinserted screw should not touch, puncture, violate, or otherwiseinterfere with nerves and other sensitive or vulnerable tissuesurrounding or adjacent to the joint (e.g., spinal canal, neuroforamen,anterior sacral cortical wall, sacral ala, or other tissue). Once thescrew is inserted into place, the driver, the guide pin and the drillguide may be removed (1212).

FIGS. 13A-F illustrate an exemplary process for fusion of a sacroiliacjoint. FIG. 13A illustrates the pre-operative portion of process 1300.Here, process 1300 begins with performing a lateral radiograph and ananteroposterior (AP) radiograph of a pelvic area (1302). For example, aFerguson's view may be obtained to view the sacroiliac joint and itssurrounding tissue. In some examples, fluoroscopy techniques may be usedto provide view or images in real time. Using the radiographs, apathology is confirmed (1304) and one or more surgical landmarks areidentified (1306). In some examples, identifying one or more surgicallandmarks may include identifying a location for implantation of ascrew. A position and a trajectory of the screw, or other implant, alsomay be determined (1308) pre-operatively.

FIG. 13B illustrates the incision and guide pin placement portions ofprocess 1300. The operation may begin with creating an incision (1310).In some examples, the incision may be approximately 2-3 cm long. Inother examples, the length and location of the incision may varydepending on the size, dimensions, composition and/or geometry of asacroiliac joint. For example, the length and placement of the incisionmay be different for a more obese patient (i.e., more posterior) thanfor a less obese patient. Once the incision is created, tissue may beseparated to access the ilium (1312). Then a guide pin may be inserteduntil it rests against the ilium (1314). In some examples, the guide pinmay be a medical grade sterile metal pin (e.g., Kirschner wire,Steinmann pin, or other metal pin) suitable for use in medicalprocedures. In some examples, the guide pin may be inserted throughtissue near or adjacent to the ilium. Once the guide pin is restingagainst the ilium at the location of implantation, it may be aligned(i.e., according to the previously determined trajectory and position)and advanced through the sacroiliac joint into a sacrum (1316). In someexamples, the guide pin may be advanced using a mallet. The guide pinshould not touch, puncture, violate, or otherwise interfere with nervesand other sensitive or vulnerable tissue surrounding or adjacent to thejoint (e.g., spinal canal, neuroforamen, anterior sacral cortical wall,sacral ala, or other tissue).

FIG. 13C illustrates the bone and joint preparation portion of process1300. Once the guide pin is in place in the sacroiliac joint, a drillguide assembly may be prepared by screwing a pin sleeve into a drillguide (1318). In some examples, the outer diameter of the pin sleeve'sshaft fits into the cannula of the drill guide, and is screwed into thedrill guide so that the drill guide and pin sleeve are coupled securely.In some examples, the pin sleeve is screwed into the drill guide untilthe tip of the pin sleeve protrudes past the tip of the drill guide. Thedrill guide assembly may be placed over the guide pin and against theilium (1320). In some examples, the drill guide assembly may slide overthe guide pin until the tip of the drill guide assembly (i.e., the pinsleeve tip, which protrudes from the drill guide tip when the pin sleeveis fully screwed into the drill guide) rests against the ilium. Once thetip of the drill guide assembly is resting against the ilium, the pinsleeve may be unscrewed from the drill guide while the drill guide isadvanced toward the ilium (1322). In some examples, the drill guide isadvanced until the drill guide tip is resting against the ilium and thepin sleeve is out of the way (i.e., the pin sleeve tip is backed awayfrom the ilium). In some examples, the pin sleeve is out of the way whenthe threads of the pin sleeve are entirely out of the drill guide head.Once it is verified that the pin sleeve is backed away from the ilium, astriker tube may be installed onto the drill guide (1324). In someexamples, the striker tube may be installed by placing it over theportions of the guide pin and the pin sleeve extending out of the drillguide head, and onto the head of the drill guide, as shown in FIG. 5.Once the striker tube is installed onto the drill guide, the strikertube may be tapped to drive the drill guide into place to engage theilium (1326). In some examples, the striker tube may be tapped using amallet, suitable hammer, or other suitable tool for tapping the flathead of the striker tube. In some examples, the striker tube may betapped more than once for the drill guide to engage the ilium. Once thedrill guide engages the ilium, the striker tube may be removed (1328),and the pin sleeve also may be removed (1330). A depth gauge may then beused to determine a depth (1332). In some examples, the depth gauge mayhave numerically-labeled markings (e.g., depth markings 604 a-604 b)corresponding to depths (i.e., at 5 millimeter intervals). In someexamples, the depth corresponds to a depth or distance that the guidepin is embedded into the bone. In some examples, the depth gauge fitsover the guide pin and onto, or against, the drill guide, as shown inFIG. 6. Then, a cannulated drill bit may be selected according to thedepth determined using the depth gauge (1334). In some examples, acannulated drill bit for drilling an appropriate-sized pilot hole may beselected according to the depth of the guide pin. For example, if aguide pin has been inserted 40 mm deep into the sacroiliac joint, acannulated drill bit configured to drill a pilot hole of 40 mm depth maybe selected. In another example, a predetermined offset may be desiredbetween the depth of the guide pin and the depth of the pilot hole, inwhich case a cannulated drill bit configured to drill a pilot hole of 40mm minus the predetermined offset may be selected. In other examples,the cannulated drill bit may be adjustable. For example, an adjustablecannulated drill bit may have markings corresponding to the numericaldepth readings on a depth gauge (e.g., depth gauge 602), the markingsindicating a desired drilling depth (i.e., depth of a pilot hole). Inthis example, the adjustable cannulated drill bit may be fitted with astop collar, as described herein, to stop the adjustable cannulateddrill bit at the desired drilling depth. In some examples, a desireddrilling depth may be the same as the depth of the guide pin. In otherexamples, the markings on a cannulated drill bit may account for apredetermined offset distance (e.g., 3 mm or other distance) from thedepth of the guide pin. For example, if the guide pin is determined tobe at a 40 mm depth, the 40 mm marking on the cannulated drill bit maycorrespond to a drilling depth of 37 mm. Once the cannulated drill bitis selected, or an adjustable cannulated drill bit is fitted with a stopcollar at the desired marking, the depth gauge may be removed (1336) andthe cannulated drill bit inserted over the guide pin into and throughthe drill guide (1338). In some examples, the cannulated drill bit fitssnugly over the guide pin. Once the cannulated drill bit is in placewithin the drill guide, a pilot hole may be created to a drilling depth(1340). As described herein, the drilling depth may be the same as thedepth of a guide pin as measured by the depth gauge, or it may bedifferent. Once the pilot hole is created, the drill bit may be removed(1342). At this point, the guide pin may be removed optionally (1344),or it may be left in place as a guide for the screw insertion portion ofprocess 1300.

FIG. 13D illustrates the screw insertion portion of process 1300. Ascrew may be selected (1346), the screw having a length corresponding tothe drilling depth. In some examples, the length of the screw may be thesame as the drilling depth. In other examples, the length of the screwmay be offset from the drilling depth by a predetermined distance (i.e.,the screw length may be a few millimeters longer or shorter than thedrilling depth. In some examples, the screw may be packed with materialbefore being implanted (1348). In other examples, the screw may not bepacked until after it is implanted. The screw may be inserted into adrill guide until the screw's tip rests against the ilium (1350). Adriver may then be inserted into the drill guide until the driverengages the screw (1352). In some examples, the driver may becannulated. In some examples, as described herein, the driver may be aTORX® or TORX®-like screwdriver. In other examples, the driver may be adifferent type of screwdriver, as may be appropriate for driving a screwwith a different type of head (e.g., PHILLIPS™, slot, flat, Robertson,hex, or other type of screw head). In some examples, the driver may behand operated. For example, the driver may be a hand operated manualdriver, as shown in FIG. 9. In another example, the driver may be apowered driver. In still another example, the driver may be ratcheting,torque-limited, or have other characteristics useful for driving a screwinto a joint. Using the engaged driver, the screw may be threaded intothe pilot hole until the screw's head stops against the ilium (1354).The implanted screw should not touch, puncture, violate, or otherwiseinterfere with nerves and other sensitive or vulnerable tissuesurrounding or adjacent to the joint (e.g., spinal canal, neuroforamen,anterior sacral cortical wall, sacral ala, or other tissue). Once thescrew is driven into the pilot hole, and into place in the joint, thedriver may be removed (1356). If no more screws are to be placed, and noadditional or secondary packing of material into the screw is to beperformed, then the drill guide may be removed, along with the guide pinif it has not been removed previously, at this time (1362).

If additional screws are to be implanted, FIG. 13E illustrates portionof process 1300 wherein another guide pin is placed using the parallelspacer instrument. With the drill guide still in place from the previousscrew insertion, a parallel spacer instrument is adjusted according to adesired spacing (i.e., between implanted screws) (1364), and is placedon the drill guide using a drill guide tube (1366). In some examples,the parallel spacer instrument may include a parallel spacer block witha drill guide tube, a sliding block with a sliding block tube, and alocking nut (as shown in FIGS. 10A-10D). In some examples, the parallelspacer instrument may be adjusted by sliding a sliding block to thedesired spacing setting on the parallel spacer block, and tightening thelocking nut to secure the sliding block in place (see FIGS. 10A-10D). Insome examples, the sliding block may comprise a drill guide tube thatfits into the shaft of a drill guide. In some examples, the drill guidetube may be cannulated to accommodate a guide pin. For example, if apreviously-placed guide pin is still in the drill guide, the drill guidetube may slide over the guide pin and into the drill guide. Once theparallel spacer instrument is placed on the drill guide, another (i.e.,a next) guide pin may be inserted through a sliding block tube until thetip of this next guide pin rests against the ilium (1368). This nextguide pin may be advanced through the sacroiliac joint into the sacrum(1370), for example, using a mallet. In some examples, this next guidepin may be advanced through tissue before it rests on the ilium at thenext location to implant a screw. This next guide pin should not touch,puncture, violate, or otherwise interfere with nerves and othersensitive or vulnerable tissue surrounding or adjacent to the joint(e.g., spinal canal, neuroforamen, anterior sacral cortical wall, sacralala, or other tissue). Once this next guide pin is in place in thesacroiliac joint at this next location, the parallel spacer instrumentmay be removed (1372). If the previously-placed guide pin is still inthe drill, it also may be removed at this time (1372). If no additionalor secondary packing of material into the already-implanted screw is tobe performed, then the drill guide may be removed from its currentposition (1374). The drill guide assembly may be re-assembled forrepetition of the bone and joint preparation and screw insertionportions of process 1300 (see FIGS. 13C-13D) at the next location wherethe next (i.e., another) guide pin has been placed.

If additional or secondary packing of material into thealready-implanted screw is to be performed, FIG. 13F illustrates thepost-insertion packing portion of process 1300. A packing tube may beloaded with an amount of material, the packing tube coupled to a plungerand having a loading port at an end (1380), as shown in FIG. 11A. Insome examples, the amount of material may correspond to a volume thatfills or substantially fills the hollow shaft of a cannulated screw(i.e., the already-implanted screw), as described herein. Also asdescribed herein, the material may include osteogenic compounds,osteoconductive materials, antibiotics, steroids, contrast materials, orother materials that may beneficial to fusing the joint, treatinginflammation or other conditions in a joint, or enabling thevisualization of the area within and adjacent to the screw. Once loaded,the packing tube may be inserted into the drill guide until the loadingport engages the screw's head (1382). The screw then may be packed withsaid material (1384). In some examples, packing the screw may includedepressing a plunger coupled to an end of a packing tube comprising aloading port at another end opposite to the plunger, the plungerconfigured to dispense said material out the loading port, for exampleinto a cannulated screw (e.g., screws 100 and 200, or the like) coupledto the loading port, when depressed. A screw packed in such a way may inturn deliver said material into a joint through openings in the screw,as described herein. Once the screw is packed, the packing tube may beremoved (1386). The drill guide then may be removed as well (1388). Ifthere is another screw to implant (i.e., another guide pin has beenplaced using the parallel spacer instrument), then the drill guideassembly may be re-assembled for repetition of the bone and jointpreparation and screw insertion portions of process 1300 (see FIGS.13C-13D) at the next location. If no other screw is to be implanted, thewound created by the incision and the implantation process may be closedusing standard surgical technique.

In other examples, processes 1200 and 1300 may be implemented with moreor fewer steps. For example, electrical activity in a patient's body maybe monitored during part or all of a joint fusion process (e.g.,processes 1200 and 1300) using various techniques for measuringelectrical potentials (e.g., somatosensory evoked potentials and otherelectrical potentials). In this example, electromyography (EMG) may beused to monitor electrical activity in muscles in the area surrounding,connected to, or otherwise associated with the joint (e.g., tibialisanterior, gastrocnemius, rectal sphincter, or other muscles). In anotherexample, part or all of a joint fusion process (e.g., processes 1200 and1300) may be performed under fluoroscopy guidance (e.g., providing aFerguson's view of the sacroiliac joint). In some examples, processes1200 and 1300 may be performed to implant multiple screws into a joint.

Although the foregoing examples have been described in some detail forpurposes of clarity of understanding, the invention is not limited tothe details provided. There are many alternative ways of implementingthe invention. The disclosed examples are illustrative and notrestrictive.

What is claimed:
 1. A screw, comprising: a shaft extending from a headto a tip and including threads disposed on an external surface of theshaft, a plurality of slots and a plurality of shaft grooves disposedlinearly with each other from approximately the head to the tip, eachslot positioned serially between a pair of shaft grooves, the pluralityof slots and plurality of shaft grooves are disposed on a plurality ofsides of the shaft at approximately ninety degrees or less from eachother, the threads are discontinuous at each slot and at each shaftgroove, each slot is formed completely through a portion of the threads,the head including an opening and the tip including another opening, theplurality of shaft grooves being configured to be guided by an internalsurface of a drill guide, and each shaft groove having a first widththat varies along the shaft, each slot having a second width that variesalong the shaft, and a first maximum width in the first width is lessthan a second maximum width in the second width; and a cannulapositioned within the shaft and extending from the opening to theanother opening, each slot extending all the way to the cannula to forma through hole opening between the cannula and the external surface, aportion of a sub-set of the plurality of shaft grooves are disposed onthe tip, the tip being formed between the another opening and a taperedend of the shaft.
 2. The screw of claim 1, wherein each slot creates anopening between the cannula and tissue surrounding the shaft.
 3. Thescrew of claim 1, wherein each slot is substantially oval.
 4. The screwof claim 1, wherein the head, the tip, and the shaft are formed using amedical grade titanium alloy.
 5. The screw of claim 1, wherein the headis configured to fit within a drill guide's cannula.
 6. The screw ofclaim 1, wherein the tapered end is operative to guide the screw into apilot hole drilled into a bone.
 7. The screw of claim 1, wherein theopening further is configured to receive a loading port of a packingplunger assembly, the packing plunger assembly configured to dispense amaterial into the cannula.
 8. The screw of claim 1, wherein the openingcomprises a plurality of grooves configured to receive a plurality oflobes on a screwdriver tip.
 9. The screw of claim 1, wherein the cannulais configured to hold a material, the material configured to enter ajoint through one or more of the plurality of slots.
 10. A screw,comprising: a shaft extending from a head to a tip and including threadsdisposed on an external surface of the shaft, a plurality of slots and aplurality of shaft grooves disposed linearly with each other fromapproximately the head to the tip, each slot positioned serially betweena pair of shaft grooves, the threads are discontinuous at each slot andat each shaft groove, each slot is formed completely through a portionof the threads, the plurality of shaft grooves being configured to beguided by an internal surface of a drill guide, and each shaft groovehaving a first width that varies along the shaft, each slot having asecond width that varies along the shaft, and a first maximum width inthe first width is less than a second maximum width in the second width,the head including an opening and the tip including another opening, thetip is formed between the another opening and a tapered end of the shaftthat does not include the threads, and a portion of a sub-set of theplurality of shaft grooves are disposed on the tip; and a cannulapositioned within the shaft and extending from the opening to theanother opening, each slot extending all the way to the cannula to forma through hole opening between the cannula and the external surface. 11.The screw of claim 10, wherein the plurality of slots and plurality ofshaft grooves are disposed on a plurality of sides of the shaft atapproximately ninety degrees or less from each other.
 12. The screw ofclaim 10, wherein each slot is substantially oval.
 13. The screw ofclaim 10, wherein each slot is capsule-shaped.
 14. The screw of claim10, wherein the opening in the head is configured to receive ascrewdriver tip having a six-point shape.
 15. The screw of claim 10,wherein the opening in the head is configured to receive a screwdrivertip having a cross shape.
 16. The screw of claim 10, wherein thecannula, the opening and the another opening are configured to fit overa guide pin.